from rest_framework import serializers

from goods.models import SKU


class CartSerializer(serializers.Serializer):
    sku_id = serializers.IntegerField(label='sku_id', required=True, min_value=1)
    count = serializers.IntegerField(label='数量', required=True, min_value=1)
    selected = serializers.BooleanField(label='是否勾选', required=False, default=True)

    def validate(self, attrs):

        # 判断商品是否存在
        sku_id = attrs['sku_id']
        try:
            sku = SKU.objects.get(pk=sku_id)
        except SKU.DoesNotExist:
            raise serializers.ValidationError('商品不存在')
        # 判断库存是否充足
        count = attrs['count']
        if sku.stock < count:
            raise serializers.ValidationError('库存不足')

        return attrs


class CartSKUSerializer(serializers.ModelSerializer):
    count = serializers.IntegerField(label='数量')
    selected = serializers.BooleanField(label='是否勾选')
    class Meta:
        model = SKU
        fields = ('id', 'count', 'name', 'default_image_url', 'price', 'selected')


class CartDeleteSerializer(serializers.Serializer):

    sku_id = serializers.IntegerField(label='商品id',min_value=1)

    def validate(self, attrs):

        #判断商品是否存在
        try:
            sku = SKU.objects.get(pk=attrs['sku_id'])
        except SKU.DoesNotExist:
            raise serializers.ValidationError('商品不存在')

        return attrs